A major input to current brake control algorithms for aircrafts is an aircraft reference speed, which may be based on an estimate of what an aircraft wheel speed would be if it was not being braked. Ideally, the aircraft reference speed equals the aircraft ground speed. However, in today's aircraft speed monitoring systems, there is generally not a direct method of determining aircraft ground speed (to use as the aircraft reference speed), because, for example, a wheel speed sensor may measure the speed of the main landing gear wheels while braking during landing. However, during braking, the main landing gear wheels may slip, and thus, the wheel speed measured by the wheel speed sensors may not accurately reflect the ground speed. As a result, the aircraft ground speeds tend to be approximations based on potentially inaccurate wheel speed measurements.